The present invention relates to a system for manufacturing semiconductor under a clean condition, which can be suitably implemented in a semiconductor production plant or the like requiring high degree of freedom from dust.
In semiconductor production plants, it has become essential to provide a dust-free (or ultra-clean) manufacturing condition with increase of integration density of products and increase of fineness of processing. Equipment for providing clean condition of semiconductor production plants thus is important. A system for providing a clean condition which is called an entire down-flow system has heretofore been employed most extensively. In this system, air having passed through a fine dust particle removal filter is caused to flow down through a room so that air in the room is cleaned with this circulation of clean air.
In this system, a large quantity of expensive filters are used to cause circulation of clean air through the entire room. Therefore, high cost is required to provide an increased cleanliness. In addition, the scale of air suction fan is inevitably increased. Furthermore, an upper limit is imposed on the cleanliness, and it is difficult to realize as high cleanliness as class 10 or below. This problem is particularly serious in semiconductor production plants for manufacturing high integration density products such as ultra LSIs or ultra ultra LSIs. For this reason, it has been proposed and practiced to provide a so-called clean tunnel in a transport section to partition the manufacturing section with respect to the other sections. In this case, however, high equipment cost is required. In addition, the borderline of cleanliness is provided only by the clean tunnel. Therefore, expected effect of providing cleanliness can not be obtained.